In gas chromatography and other fields, it is necessary to control the flow of one or more fluids by means of an system of control valves. The configuration of the system may be quite complex, and the valves themselves are often required to be very small and precise in operation. To meet this requirement, the internal volume of the valves should be very small.
Moreover, in many applications all surfaces which can come into contact with the controlled fluid must be inert so as to avoid contaminating the fluid. Substances which react with or absorb the controlled fluid can seriously distort the results of a gas chromatography system, for example, since the required sensitivity of those results may be of the order of a few parts per billion, or even less.
It is also desirable that the operation of the valves be as simple as possible and that the valves have a long service life (i.e., numerous openings and closures) without failure.
U.S. Pat. No. 4,353,243 to Martin, issued Oct. 12, 1982, describes an arrangement in which a plurality of diaphragm valves are linked by a peripheral channel formed in the surface of a solid plate. While useful in some applications, this system does not have the flexibility of being adaptable to extremely complex arrays and interconnections between a large number of valves.